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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Lecram on May 01, 2017, 08:44:02 PM
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I often read '1C' charging when it regargs fast charging for the Zero. But what exactly does 1C mean?
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It means charging at 1x the hourly capacity.
Battery cap is 100Ah, it means charge current is 100A and battery will be full (from empty) in 1 hour theoretically.
In this example, 0.5C charging means 50A during 2h...
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It means charging at 1x the hourly capacity.
Battery cap is 100Ah, it means charge current is 100A and battery will be full (from empty) in 1 hour theoretically.
In this example, 0.5C charging means 50A during 2h...
Great, thank you!
Why is this so important for charging the Zero?
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Because 1C is the highest possible charge current. Beyond this value the pack may be damaged.
Plese note that the highest discharge current (at least when fully charged) is specified to 7C by Zero.
It is very usual that batteries can be discharged quicker than recharged. Batteries for electric cars featuring very quick charge through chademo or combo within 30 minutes are designed for higher charge rates like 2C, at the expense of other features, for example energy density (bigger, heavier pack).
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Because 1C is the highest possible charge current. Beyond this value the pack may be damaged.
Plese note that the highest discharge current (at least when fully charged) is specified to 7C by Zero.
It is very usual that batteries can be discharged quicker than recharged. Batteries for electric cars featuring very quick charge through chademo or combo within 30 minutes are designed for higher charge rates like 2C, at the expense of other features, for example energy density (bigger, heavier pack).
Farasis has been testing cells and they can handle 3C without damage, but the Zero packs have been designed with a more conservative 1C limit, reflecting the prior understanding of the cells. The circuitry will disconnect the contactor if it detects more than 1C charging, so that's the limit we have to go by. So, for example, for my 11.7 kwh battery, with 10 kwh usable, we limit charge rates to 10 kw. I've got two j-plug inlets.
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Because 1C is the highest possible charge current. Beyond this value the pack may be damaged.
Plese note that the highest discharge current (at least when fully charged) is specified to 7C by Zero.
It is very usual that batteries can be discharged quicker than recharged. Batteries for electric cars featuring very quick charge through chademo or combo within 30 minutes are designed for higher charge rates like 2C, at the expense of other features, for example energy density (bigger, heavier pack).
So that means that when a Powertank is used, the 1C value is higher, about 124 Amps, is that right? If that is right, the battery can be charged at about 14Kw's
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We should perhaps also point out for the uninitiated that even charging at a 1C rate can be damaging under some circumstances, such as when the SoC is near the minimum or maximum. A typical "smart charger" will start off with a slower charge if the battery is well discharged, transition at some point to "bulk charging" at (perhaps) the 1C rate, and then taper off at the higher end by transitioning from constant current (CC) to constant voltage (CV) charging.
Which is a long-winded explanation for why "1C" charging can't charge your battery from 0% to 100% in an hour. But it probably can charge from 30% to 80% in 1/2 hour.
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Approximately 1C charging or more would also make the Zero motorcycles usable beyond half their normal range (have to return to overnight charging after using 50% of the battery or wait for a long time at the destination before going back). I'm keeping my fingers crossed Zero will bring back DC charging, or offer 22/11kW AC charging soon.
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Because 1C is the highest possible charge current. Beyond this value the pack may be damaged.
Plese note that the highest discharge current (at least when fully charged) is specified to 7C by Zero.
It is very usual that batteries can be discharged quicker than recharged. Batteries for electric cars featuring very quick charge through chademo or combo within 30 minutes are designed for higher charge rates like 2C, at the expense of other features, for example energy density (bigger, heavier pack).
So that means that when a Powertank is used, the 1C value is higher, about 124 Amps, is that right? If that is right, the battery can be charged at about 14Kw's
Yes. However, there is also a 100 amp fuse that is not easy to get to or replace. To get past it you need to wire the fast charger to your controller rather than using the aux charge port.
The 1C limit enforced by the BMS is relative to nominal capacity. So a 2014 S ZF11.4 is 10kWh nominal so can be charged at 10kW. A 2017 S ZF13 is 11.4kWh so can be charged at 11.4kW. A 2016 S ZF15.9 (power tank) is 14kWh nominal so can be charged at 14kW.
Keep in mind that at 95V, 100 amps means 9.5kW max or you blow the fuse. Once pack voltage goes up to 110V you can charge at 11kW before you blow the fuse. Thus, I recommend to wire anything over 9kW to the controller rather than through aux charge port.
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Ah the joys of being a 2013 battery owner :D Been charging through my controller since I blew my Aux fuse years ago with my RSP2000 charging stack lol
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Ah the joys of being a 2013 battery owner :D Been charging through my controller since I blew my Aux fuse years ago with my RSP2000 charging stack lol
Aka learning the hard way 😉
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Unofficial manual entry: http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate (http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate)
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Unofficial manual entry: http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate (http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate)
Good write up....I think this entry warrants an asterisk with a mention of the 100 amp fuse.
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Unofficial manual entry: http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate (http://zeromanual.com/index.php/Unofficial_Service_Manual#C-rate)
Good write up....I think this entry warrants an asterisk with a mention of the 100 amp fuse.
It's in a nearby section under Charging: http://zeromanual.com/index.php/Unofficial_Service_Manual#Charging_Fuse (http://zeromanual.com/index.php/Unofficial_Service_Manual#Charging_Fuse)
I'll figure out a clearer organization at some point. There are many concepts that link with each other.
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Has anyone ever considered to replace the fuse for a 125A (or other higher Amp) fuse?
I know that Zero would never support this, but Zero also does not support other chargers than theirs.
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Has anyone ever considered to replace the fuse for a 125A (or other higher Amp) fuse?
I know that Zero would never support this, but Zero also does not support other chargers than theirs.
I think it is much easier to add a 125 or 150 fuse to the controller terminals and an Anderson connector that supports that amperage.
I think I saw a thread where someone put a circuit breaker to the controller terminals.
The controller terminals are easily accesable, you just take of the seat and the controller cover and there you have some nice connections.
I am considering doing an extra fused connection to the controller to add 2 more Flatpack S units to my Quad unit. However I think that would put me above 1C. I now have around 8 - 8.5 kW charging (4*1,8 kW for the flatpacks and 1,3 kW for the onboard) and with 2 more flatpacks that would get me to 11 kW without the onboard.
Does anyone know if the 1C limit is determined from maximum capacity, nominal capacity, the Ah rating of the pack or the Ah rating of the cells ?
The max capacity for the 2014SR is listed in the brochure (and on the pack) as 11.4 kWh
The nominal capacity is listed in the app as 10.4 kWh (10.0 on the specs page)
The Ah at 100% SOC is listed in the app as 91 Ah, however the cells are rated as 4* 25Ah = 100 Ah (farasis datasheet)
If 1C is 91A (from the 91Ah rating in the app) I wouldn't have to think about an additional fuse with higher rating to get a little more charging power. The 100A standard fuse would suffice.
What would happen if you go (a little) above 1C, I presume the BMS would open the contactor to protect the battery pack. but would that happen at exactly 1C or at 1.1C ? I guess nobody has tried or experienced that.
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Bypassing the aux charging port raised some questions from my part. Does the BMS then still report the charging current?
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Bypassing the aux charging port raised some questions from my part. Does the BMS then still report the charging current?
I think it does, I think the current sensor is inside the battery pack, otherwise it would not be able to detect regen currents. I would have to check but I think the aux charging cables end up at the side of the contactor parallel to the controller wires. The 100 A fuse is just there to protect the Anderson connector (rated for 110A?) and the cabling.
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I think it does, I think the current sensor is inside the battery pack, otherwise it would not be able to detect regen currents.
Or discharge currents for the motor, either, which it has to monitor. Actually, I'm sure the current sensor is inside the battery pack, mine had to be replaced when the battery was rebuilt.
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What I've learned from the experts this week...
The BMS current sensors are not accurate to those amperages at greater than 1C rates, so you cannot trust their exact values but yes they do still give a general indication of more power or less power flowing through.
The BMS contactor opens at greater than 1C for more than 30 seconds (protected from starting a fire by an internal 300A fuse) and note that 1C is defined in terms of amps. You might only trip that condition for a portion of the charging process because of how that is measured. The limitation of the ZF13.0 pack chemistry is said to be 3C but possibly because of design limits for accuracy of the current sensing circuit, it is not reasonable to expect the 1C limit to be changed for existing model years (but that doesn't mean you couldn't ever see it in future Zero model years).
The C-rating is linked to amp-hours so the only reasonable way to get faster than 1C charging on an existing Zero is to add more battery capacity to raise the value of the 1C rating.
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There are TWO check points if I recall correctly. (at least on my 2013)
The Controller has a max regen amperage setting. If you do something to this setting alone it does NOTHING. This is because there is a regen setting preconfigured to overwrite the controller defaults coming from the MBB ... and if I recall you cannot change this; there is no "set" command for this value .... so it might come from the main BMS.
What you can do is set the controller to have the equivalent of NULL data for the overwrite variable and the controller can then take over the max regen.
I know because I had to do this when installing my "foot brake" transducer regen lever. My amperage had to be set to 90 in order to get the same affect as default regen behavior. Even though it is set to 90 though I haven't seen it go over 60 for a brief moment then normalizes somewhere in the 40's if I recall correctly.
When I get my CA-HC installed I will know better for sure :D
Oh and if you haven't figured it out there is like current senors all over the bike including the battery modules, the main BMS, and the controller. ;)
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I suspect that even a Power Tank added to the bike doesn't effectively yield a 25% increase in C-rate if the inaccuracies in current measurement are right, and additionally the load balancing between the main power pack and the extra module might be imperfect sometimes.
But Burton and others' info sounds right to me based on what I've heard. Trying to improve the explanation will take time.
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Terry is able to use 4 super chargers and the onboard to charge at 125A or 14.5 kW with his power tank.
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Terry is able to use 4 super chargers and the onboard to charge at 125A or 14.5 kW with his power tank.
How are these connected to the battery? Partially through the Anderson connector and partially direct to the controller?
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Terry is able to use 4 super chargers and the onboard to charge at 125A or 14.5 kW with his power tank.
How are these connected to the battery? Partially through the Anderson connector and partially direct to the controller?
I think it's one pair of chargers into the port (downstream of the fuse with the onboard charger) and one pair at the controller terminals.
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When connecting to the controller is there an inline fuse used? And if so what are the limits to charging through the controller?
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When connecting to the controller is there an inline fuse used? And if so what are the limits to charging through the controller?
Also interested in the question if you've put another fuse in.
As the discharge current (up to 750A on MY17) also runs through the controller terminals, you won't run into a limit there with charging. I think there are M6 or M8 bolts.
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Using a fuse or a breaker is definitely advised. Remember a fuse a breaker is to prevent wire from overheating and starting a fire so the fuse or breaker should never exceed the rating of the wire and ideally is sized to be just a little bigger than the load.
In other words if you want 125 amp charging use a 150 amp breaker or fuse not a 200 amp.
Last, the fuse or breaker should be as close to the voltage source as possible. In this case you connect to the controller so it should be close to the controller.
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No controller connections have been fused or breakered in any installations I've seen. The primary safety feature at that point is only the contactor, so yes this requires some more than casual care in all cases, and is not recommended for the average user.
This also means that you don't get to exceed the battery C-rate (and neither does regen by default!). It's just a way to get to 1C itself, and is best used as an augment for the primary charging happening through the accessory charging port (unless you have a 2013 battery in which case that port is only rated for 30A).
For safety features, I recommend the accessory charging port; getting the fusing or breaker selection right adds complication and components to the job which means you really will need a professional (engineer) involved.
I've described some of it on the wiki in an appropriate section:
http://zeromanual.com/index.php/Advanced_Modifications#Charging_Through_Sevcon_Controller (http://zeromanual.com/index.php/Advanced_Modifications#Charging_Through_Sevcon_Controller)
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No controller connections have been fused or breakered in any installations I've seen. The primary safety feature at that point is only the contactor, so yes this requires some more than casual care in all cases, and is not recommended for the average user.
This also means that you don't get to exceed the battery C-rate (and neither does regen by default!). It's just a way to get to 1C itself, and is best used as an augment for the primary charging happening through the accessory charging port (unless you have a 2013 battery in which case that port is only rated for 30A).
For safety features, I recommend the accessory charging port; getting the fusing or breaker selection right adds complication and components to the job which means you really will need a professional (engineer) involved.
I've described some of it on the wiki in an appropriate section:
http://zeromanual.com/index.php/Advanced_Modifications#Charging_Through_Sevcon_Controller (http://zeromanual.com/index.php/Advanced_Modifications#Charging_Through_Sevcon_Controller)
Yes, that really surprised me that many of the installs to the controller I have seen others do did not have a fuse or breaker. Actually, there is one person that posted about using a breaker but I think the connection was to the monolith not the controller....which is effectively the same. Both the onboard charger and the aux port charging go through the 100 amp fuse. Bypassing that means you are relying on the contactor which can't open as quickly as a fuse or breaker blows....and if there's a LOT of current for some reason the contactor can get welded shut where obviously a fuse or a breaker would sill blow.
Having worked professionally doing automotive electronics installation and seeing fires start from much lower current than being discussed here I myself would never do a fast charger install to the controller or any other point that bypasses the aux charge port fuse without putting in a fuse or breaker (I will probably use a breaker so that I don't have to carry a fuse to keep from potentially getting stranded).
In my opinion, anyone that can't figure out how to properly install a fuse or breaker should only be fast charging through the aux charge port. Which is essentially what I think you are saying when you said to use aux charge port for safety features. Again, it's just seeing so many really experienced people doing the controller install without a fuse or breaker that really surprised me.
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The contactor should open for gradual loads exceeding the rating for a period of time... if you have a dead short then the contactor does not have time to activate and the battery design 300A fuse will go.
You should not have two fuses one inline with the other, because you don't know which one will be tripped on a dead short. Fast acting breakers might or might not be effective, but they also can fuse themselves.
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The contactor should open for gradual loads exceeding the rating for a period of time... if you have a dead short then the contactor does not have time to activate and the battery design 300A fuse will go.
You should not have two fuses one inline with the other, because you don't know which one will be tripped on a dead short. Fast acting breakers might or might not be effective, but they also can fuse themselves.
The Zero design has two fuses inline with each other...the 300 amp fuse you mentioned in the battery and the 100 amp fuse in the aux charge port. If you connect directly to the controller you are bypassing the 100 amp fuse therefore you should put a fuse or a breaker on your connection to the controller. Or don't. But the fuse is there to keep the wire from overheating and starting a fire, not to protect the battery or any of the bike electronics. I'm not worried about gradual loads exceeding the 1C rate, in which case the contactor will open as you describe. I'm worried about hot wire starting a fire because of a short. In a dead short the one that will be blown will be the one with the lower rating.
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Also, that 300 amp fuse you referenced must be per brick otherwise an SR wouldn't be able to pull 600 amps from the monolith. So 300 amp x 4 = 1200 amps before you blow a fuse. The wire you are using to connect to the controller and charge at 120 amps isn't rated for 1200 amps and it's going to get really hot before you blow a fuse in the battery. Not to mention I would hate to blow that fuse in the battery cause it likely means that battery needs to be replaced as the fuse isn't easily accessible. Which is why the onboard charger and aux charge port have their own 100 amp fuse (not each...they share the 100 amps but it's separate from the battery fuse). If you connect to the controller you should use a fuse or a breaker....that's just my recommendation. Do with it what you will.